After looking around more I realised that! Other than coilovers what brand gas strut would be best to go for?
Do you have a ballpark budget?
Thing to remember is that this was a $75k car new and that MRC wasn't standard fitment on even Clubsports or other HSVs, so MRC probably would have accounted for maybe a thousand(ish) of that price above standard shocks, particularly with looms and modules. Does that mean you need to spend that amount? No, but whatever you buy to replace it may not replicate MRC suspension, particularly if you're spending $66 per corner in the case of the Ultima shocks (which IMHO I wouldn't even spend that little putting those in a daily beater). Not that MRC is the greatest or anything.
As above, KYBs at a minimum, I think they're a lot better than Monroe and a lot of them came out of Japan, not sure if that's the case anymore. If you decide you want to spend up and go down the coilover route (~2k), you should talk to MCA and Shockworks as they will build coilovers in Australia specific to your use (they can make them comfy if that's what you want) and will probably be far better than MRC, just without the in cabin control.
Answering your original question though, the MRC and non-MRC shocks look almost exactly the same, so It's probably a safe bet. Worst case scenario you put the old shocks back in and get the normal springs later.
